OCF queue list needs to be managed synchronously.
This patch uses our own mutex to achieve that because we cannot rely on
ocf_mngt_cache_lock() as it may produce deadlocks when using
cleaner.
Alternative way would be to use trylock, but
we need to register a poller for it and do locking concurently
which doesn't seem to be possible in callbacks of io channel.
We agreed with OCF team that we are going to change this part
when OCF will deliver safe ocf_mngt_cache_lock() function.
This patch fixes a very rare failure on our CI that looked like this:
```
04:33:02 vbdev_ocf.c: 134:stop_vbdev: *NOTICE*: Not stopping cache instance 'Malloc0' because it is referenced by other OCF bdev
04:33:03 MalCache1: Core core2 successfully removed
04:33:03 MalCache1: Stopping cache
04:33:03 MalCache1: Done saving cache state!
04:33:03 src/ocf/mngt/ocf_mngt_cache.c:1576:2: runtime error: pointer index expression with base 0x000000000000 overflowed to 0xffffffffffffffa8
04:33:03 #0 0x7f3c52d54c26 in _ocf_mngt_cache_stop src/ocf/mngt/ocf_mngt_cache.c:1576
04:33:03 #1 0x7f3c52d5579f in ocf_mngt_cache_stop src/ocf/mngt/ocf_mngt_cache.c:1657
04:33:03 #2 0x7f3c52cbe9f4 in stop_vbdev /var/jenkins/workspace/NVMe_tests/nvme_phy_autotest/spdk/lib/bdev/ocf/vbdev_ocf.c:147
04:33:03 #3 0x7f3c52cbf4a0 in vbdev_ocf_destruct /var/jenkins/workspace/NVMe_tests/nvme_phy_autotest/spdk/lib/bdev/ocf/vbdev_ocf.c:216
```
Change-Id: Id6fafb444958f3becdc480e44762074c6c081e1f
Signed-off-by: Vitaliy Mysak <vitaliy.mysak@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/450682
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
244d6e3daa